123

CAPTIVITY BEHAVIOUR AND POST-NATAL DEVELOPMENT OF THE SHREW CROCIDURA BICOLOR

BY

W. F. H. ANSELL, F.Z.S. Came and Fisheries Department, Northern Rhodesia

[Accepted 13th November, 19621

Captivity habits of Crocidura bicolor are described, including birth of a litter. Post- natal development of the young was found similar to that of Crocidura hirta, though somewhat quicker. The parent, already adult when captured, lived 332 days thereafter, and her surviving mala offspring died at the age of 375 days. No further breeding took place.

CONTENTS

Introduction .. .. .. .. . . Feeding .. .. .. .. .. . . Other activity . . .. .. .. .. Birth of young . . .. .. .. . . Appearance at birth and subsequent development Caravanning . . . . .. . . . . Weaning , . .. .. .. .. . . Miscellaneous . . . . .. .. .. References , . .. . . .. . . .. Postscript , . .. .. .. .. ..

Page .. .. 123 .. .. 123 .. .. 124 . . .. 124 .. .. 125 .. . . 125 .. . . 125 .. . . 127 .. . . 127 . . . . 127

INTRODUCTION

Breeding information about Crocidura bicolor Bocage in central Africa has hitherto consisted of a single record of lactation during April (Ansell, 1960, p. 5 ) and some unpublished data from material in the National Museum of Southern Rhodesia, Bulawayo, viz. four foetuses on 24th November 1955, and another pregnant female (number of foetuses unstated) on 12th December, 1953 (Meester, in press) ; Vesey-FitzGerald (1962) had one alive for a short time at Abercorn, but otherwise there is no previous captivity record.

On the morning of 16th October, 1960, at Kabompo, Northern Rhodesia (locus 13244-1) I found a female swimming in a sunken drum of water into which she had fallen. After being rescued she soon settled down in a wooden box with a window of perforated zinc in front and a partition about 24 inches high near the back. An automatic drinking bottle (inverted, with an inch of glass tubing inserted through the rubber cork) was provided, from which she drank frequently, but a small open pot of water was apparently not touched. A little dried grass was put into the smaller compartment as bedding, and the whole floor was strewn with sand.

FEEDING

The shrew was fed on a basic diet of finely chopped fresh raw beef, given morning and evening, on which she thrived. No measurement of the quantity

124 W. F. H. ANSELL

consumed could be made. To supplement the meat insects were given as and when available, including meal worms which, though strange at first, were soon eagerly consumed.

Imagines of small Coleoptera, small to medium-sized Lepidoptera, hyinenopterous ants, Mantidae, Ichneumonidae, Tabanus sp., and a species of scercopid, were readily accepted.

The female and her surviving offspring were subsequently kept on a diet of beef and med wornis at the British Museum (Natural History) and later on meal worms only at the London Zoological Gardens. Marlo\v (1955, Table 2) recorded that his captive Crocidura Jlavescens herero St. Leger (C. occidentalis zuleika Dollman, see Meester, 1962) definitely refused only aposeniatic forms, Lepidoptera larvae with irritant hairs, and Zygoptera, among a variety of invertebrates offered ; and, of several vertebrates, refused only the flesh of Poecilogale albinucha Gray, and of Crocidura itself. He found that viability increased markedly when the meat diet was supplemented by invertebrates, though even so none of his shrews survived longer than 67 days after capture.

C. bicolor was found to be very sensitive t o the movements of insects, and apparenbly relied 011 touch and hearing more than sight, and perhaps even more than scent, in locating prey. Marlow (1955) thought that C. occidentalis hunted by scent done, though he also noted that hearing w a ~ acute in the speoiee.

House flies* and all Orthoptera offered were refused.

OTHHIR ACTmTY

Defecation and urination were apparently concurrent, and took place at short intervals, sometimes even while feeding. A single pellet was normally deposited, and there waa some preference for the coriiers of the box, though no one place was used exclusively.

Activity was both nocturnal and diurnal, though no detailed assessment of the rhythm could be made. Marlow (1955) found C. occidentalis mainly nocturnal, though some of his specimens were trapped by day, and there was at least some diurnal activity in captivity.

C. bicolor climbed well, but in the wild state this would probably be limited to olambering over such objects as rocks and fallen branches, rather than olimbing trees and bushes.

BIRTH OF YOUNU

At the time of capture (16th October) the female was seen to be heavily pregnant, and on the same day she gave birth to a litter of three, between 6 p.m. (18.00 hrs.) and 10.46 p.m. (22.45 hrs). She was seen licking the cloaca shortly afterwards, perhaps eating the placenta.

Birth took place on the dried grass provided, but no proper nest was constructed. After some hours I put some of the grass into the tray of an empty match box, and placed the young therein, where they remained until able to move about independently. The female was most attentive to her

* Dr F. A . Turk (Ann. Rep. R. Cornwall Polytechnic Soc. 126tl1, 1959 : 52) has recorded that his captive 8ore.z araneus caatafleus L. would @talk, capture, alid @at bluehuttle and green- bottle flies.

BEHAVIOUR AND POST-NATAL DEVELOPMENT OF CROCIDITRA BICOLOR I 26

young and suckling was frequent, alternated by activity auay from them. The yoiiiig (lid not necessarily all siicklca at the same time, and it was also noticed that while feeding tlieiii t,lit? parelit, ivoiild t,alce niiy insect placed witliiii reach, wash her face, or (,v(:ii a1q)ear to tloze a t times.

Although tliiriiig the first, fen. days they w t m iiot touched by hand, this pccautioii was prohably uiiiicwss;try, as in dire course all proved amenable to handling, and human sceiit on the young caused no anxiety whatever to the parent.

When only a few hours old niiv of the yoiing holding on to a nipple might be dragged away from the iicxst, wliich Iinpl)t.iie:(l a t least twice when I was watcluiig. ‘l’he first tinit? 1 rt~p1:ieetl the i i i f a i i t , but thereafter the inothcr did this for herself.

APPEARANCE AT BIRTH AND SUBSEQUENT DEVELOPMENT

A t birth the young were pink, with head and body length about 20 mm, the head being proportionately large. They were blind, but the eyes showed dark beneath the closed lids. Tho belly skin was almost transparent. Mystacial vibrissae were present, but otherwise the young were naked. The tail was short, the snout short and blunt, and the ears small, thick, and simple in form. In all these features they closely resembled Crocidura hirta Peters described by Meester (1860) but, while his were stated to have been completely helpless and to have crawled only on the second day, the infant C. bicolor were fairly active, and even able t o attempt crawling a little, soon after birth.

By the second morning one was dead, the stomach greatly distended with watery fluid, but the other two were strong and thriving well. Their sub- sequent development is described, and comparison made with Meester’s data on C. hirta, in the accompanying table. Marlow (1955) had no success in rearing a litker born to one of his C. occidentulis, SO post-natal growth in that species remains unrecorded.

CARAVANNINNO

Caravarining (c.f. ICIeestt1r, I!)60) was first attempted at seven days old, and was thertAaftc.i- ot)srrvcd ii1) to foiirtwii (lays. ‘f’hoiigh occasionally the yoling were’ w e i i o i i e I)ehiiid tlw other, t81iv i i s i i d i i i t i i i i i t ~ of caravniiniilg in this species, a t least where thcrc. itl’e only two, is evidently o ~ i v on rnch side of the parent. O n c ~ when the femnlc niovetl of?’ unexpectedly one of the young grabbed hcr side-the nearest part a t the time. It is presumed that the female must have replaced the youiig when inadvertently dragged auay from the nest (see above) I)y carrying them in her mouth. But there is no indication that she carried them about at any other time prior to caravanning, as Meester noted in his C. hirtn. Perhaps she never anticipated any threat to her young.

WEANING

From eleven days noticeably more meat was taken, though the young were not Seen to feed until fourteen days old, and the extra consumption may have been by the parent due to increased demand on her in suckling. At fourhen

126 W. F. H. ANSELL

TABLE Comparison with

Date Age in days Physical development Behaviour Croeidura hirta (Meester, 1960)

~ ~ ~~~

Oct. 0 3 young born. For ap- A t t e m p t s t o Able to crawl only 16th pearance a t birth see crawl not long on second day.

text. after birth. - 18th 2 One dead by morning, Survivors strong

stomach distended with and well. watery fluid.

22nd 6-7 Dark pigment above ; Walking some- Walked5-6thday. to short hairs and some what unsteadily Covered with short 23rd guard hairs above ; feet ( m a y h a v e hairs 7-8th day.

well haired ; facial vi- walked earlier as Hearing present brissae well developed ; not observed on 7-8th day. below still almost naked. 5th day).

23rd 7 First attempt Ceravanning first at c a r a v a ~ i n g observed 8 - 9th (see text). day.

24th 8 Ears getting complex ; ventrally covered with fine hair ; side glands indicated by small white tufts ; approx. size (mm): HB.44, 42 ; Tail 20, 22 ; HF (s.u.) 9, 9.

26th 10 Eyes open by evening. Eyes open 12-13th day.

27th 11 Ears thin and complex, Independent of Front incisors not practically as adult; n e s t ; a c t i v e , up until 13th day. front incisors and at least able to cross 24 some other teeth up ; inch partition snout no longer blunt ; unaided. in general appeerance like adult except for smaller size.

28th ~

12 Observed wash- ing themselves.

30th ~

14 First seen to feed; squeaking Caravanning up and chattering to 18th day. when excited; still caravan- ning.

31st 15 Not much smaller than Still suckling a Weanedat l8days parent. l i t t l e , though (all teeth then

almost entirely erupted). independent.

BEHAVIOUR AND POST-NATAL DEVELOPMENT OF CROCIDURA BICOLOR 127

days the young killed a large hippo fly (Tabanus sp.) which proved too tough for them to chew unaided, though one later joined the adult in eating it. On the same day they nibbled a little rolled oats, and joined the parent in consum- ing a large moth. Thereafter weaning was rapid, though suckling was still observed at fifteen days.

MISCELLANEOUS

After weaning the young spent much of their time on top of the water bottle, in the half-inch space between i t and the lid of the box (?for coolness). They were sometimes joined by the parent, though she spent most of her resting time in the nest box. At nineteen days old the young were as large as the adult, and the larger one even exceeded her by the twenty-first day. The post-natal growth is evidently similar to that of C. hirta, but somewhat quicker.

On 23rd December, 1960, I brought the adult and one young male to England (the other having meantime escaped). They were kept a t the British Museum (Natural History) -by Dr W. P. Crowcroft until subsequently trans- ferred to the London Zoological Gardens, the first of the species received there.

The female died on 11th September, 1961, having been in captivity 332 days, and the male died on 25th October, a t 375 days of age. Cause of death was not ascertained in either case (W. C. Osman Hill, in litt.). The female carcase was eaten by the male, but i t does not follow that he killed her, for carrion feeding is well known in Crocidura.

It was regrettable that hopes of further breeding when the young male had reached maturity were not realised.

The skull of the female is now in the British Museum (Natural History) (No. 1963.44), and the infant which died at two days old is preserved as a spirit specimen in the National Museum of Southern Rhodesia, Bulawayo (No. 18775).

REFERENCES

ANSELL, W. F. H. (1960). MARLOW, B. J. G . (1955).

MEESTER, J. A. J. (1960). MEESTER, J. A. J. (in prom).

MEESTER, J. A . J. (1962).

VESEY-FITZGERALD, L. D. E. F. (1962).

Jfammals of Northern Rhodesia. Lusaka, N.R. : Government Printer. Observations on the herero musk shrew, Crocidura flauescens herero

St. Leger, in captivity. Proc. zool. SOC. Lond. 124 : 803-808. Shrews in raptivity. Afr. Wild Life 14 No. 1 : 57-63.

A systomatir revision of tho shrew genus Crocidura in Southern

A taxonomic rtwision of Southern African Crocidura (Mammalia, Africa (doctorate thesis).

Insectivora). Ann. Mag. nut. His t . (13) 4 : 561-571. Black Lechwe 3 (3) : 16-17.

POSTSCRIPT

Since the above was submitted a further breeding record of Crocidura bicolor has been obtained, from the Nyasaland side of the Nyika plateau, about 10" 35'S., 33'45'E. This was a female found about mid-day by the roadside on 15th December, 1962, which contained five foetuses, crown-rump length 10mm, i.e. about half the natal length of the litter recorded above. The specimens are now in the National Museum, Bulawayo (No. 20004).